This may be part of the pathology report to help grade the cancer. It refers to the growth of a tumor along the nerve (perineural) branches of the prostate gland. This path may act as a highway, allowing the tumor to escape outside the confines of the prostatic capsule. Many believe the presence of perineural is a generally recognized as a poor prognostic factor in prostate cancer. It has been shown in some studies to shorten the time between treatment and recurrence. It is a factor, if known, to consider in the treatment decision.
Perineural invasion a feature not uncommonly seen in needle biopsies and radical prostatectomy specimens (more often in prostatectomy specimans). Perineural invasion may be seen with any prostate cancer Gleason but more often in the Grade 4 and 5 variety.
Some believe it puts the cancer into a more advanced stage. From " Int J Radiat Oncol Biol Phys. 2007 Jul 15;68(4):1059-64. Epub 2007 Mar 29." I quote "CONCLUSIONS: Perineural invasion may be useful for risk-stratification of prostate cancer. Our data suggest that low-risk patients with PNI on biopsy may benefit from treatment typically reserved for those with intermediate-risk disease. In addition, men with high-risk disease and PNI, who are contemplating surgery, should be informed of the high likelihood of having an indication for postoperative radiation therapy."
Rev Urol. 2000 Spring; 2(2): 87–90. PMCID: PMC1476100
The Significance of Perineural Invasion Found on Needle Biopsy of the Prostate: Implications for Definitive Therapy
Steven R Potter, MD and Alan W Partin, MD, PhD
The Brady Urological Institute, The Johns Hopkins Hospital, Baltimore
The pathologic assessment of perineural invasion (PNI) of prostate needle biopsy specimens is relatively reproducible, requires no new technology or equipment, and is relatively inexpensive. The finding of PNI at biopsy has created excitement as a potential preoperative predictor of extraprostatic tumor extension. PNI is defined as the presence of prostate cancer tracking along or around a nerve within the perineural space (Figure). Although the finding of PNI on pathologic analysis of a radical prostatectomy specimen has no significance, the importance for treatment planning of PNI found on prostate needle biopsy has been a source of considerable debate. Since PNI is a major mechanism of prostate cancer extension from prostatic parenchyma to periprostatic soft tissue, PNI extensive enough to be sampled on needle biopsy may signal an increased likelihood of extraprostatic extension of cancer or, ultimately, of cancer recurrence.
Click "here" to read the full study.
The Prognostic Significance Of Perineural Invasion In Prostatic Cancer Biopsies
Article Date: 11 Jan 2007 - 0:00 PST
UroToday.com- Whether perineural invasion (PNI) identified in prostate cancer (CaP) biopsies is associated with disease recurrence is unclear from the literature. In an attempt to resolve this uncertainty, a systematic review was performed by Dr. Patricia Hamden and colleagues in the UK and published in the online edition of Cancer. What they found was that variable study design, execution and reporting excluded a definitive meta-analysis, but evidence suggests that PNI in biopsies was a significant prognostic indicator.
Click "here" to read the full article.
You can also go to PubMed and enter ["perineural invasion" AND prostate] without the brackets where it says Search PubMed for_______________ enter the search term.
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Information You Should Read
Stanford Univ. video on PCa
The Prostate - What, Where
The Prostate Biopsy
How To Tell a "Physician Artist"
The Doctors Appointment
Insignificant Cancer
Vocabulary, Glossary, etc.
Tables, Tests, Markers etc.
Gleason Info and Partin Tables
PSA - What it is and means
Locally Advanced Cancer
BPH
Prostatitis
Other Diagnostic Tools
Veterans Information
